refactored imklog linux driver, now combined with BSD driver

The Linux driver no longer supports outdated kernel symbol resolution,
which was disabled by default for very long. Also overall cleanup,
resulting in much smaller code. Linux and BSD are now covered by a
single small driver.

1 files changed, 0 insertions, 485 deletions

diff --git a/plugins/imklog/ksym_mod.c b/plugins/imklog/ksym_mod.c
deleted file mode 100644
index 82978892..00000000
--- a/plugins/imklog/ksym_mod.c
+++ /dev/null
@@ -1,485 +0,0 @@
-/*  ksym_mod.c - functions for building symbol lookup tables for klogd
- *  Copyright (c) 1995, 1996  Dr. G.W. Wettstein <greg@wind.rmcc.com>
- *  Copyright (c) 1996 Enjellic Systems Development
- *  Copyright (c) 1998-2007 Martin Schulze <joey@infodrom.org>
- *  Copyright (C) 2007-2009 Rainer Gerhards <rgerhards@adiscon.com>
- *
- * This file is part of rsyslog.
- *
- * Rsyslog is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * Rsyslog is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Rsyslog.  If not, see <http://www.gnu.org/licenses/>.
- *
- * A copy of the GPL can be found in the file "COPYING" in this distribution.
-*/
-
-/*
- * This file implements functions which are useful for building
- * a symbol lookup table based on the in kernel symbol table
- * maintained by the Linux kernel.
- *
- * Proper logging of kernel panics generated by loadable modules
- * tends to be difficult.  Since the modules are loaded dynamically
- * their addresses are not known at kernel load time.  A general
- * protection fault (Oops) cannot be properly deciphered with 
- * classic methods using the static symbol map produced at link time.
- *
- * One solution to this problem is to have klogd attempt to translate
- * addresses from module when the fault occurs.  By referencing the
- * the kernel symbol table proper resolution of these symbols is made
- * possible.
- *
- * At least that is the plan.
- *
- * Wed Aug 21 09:20:09 CDT 1996:  Dr. Wettstein
- *	The situation where no module support has been compiled into a
- *	kernel is now detected.  An informative message is output indicating
- *	that the kernel has no loadable module support whenever kernel
- *	module symbols are loaded.
- *
- *	An informative message is printed indicating the number of kernel
- *	modules and the number of symbols loaded from these modules.
- *
- * Sun Jun 15 16:23:29 MET DST 1997: Michael Alan Dorman
- *	Some more glibc patches made by <mdorman@debian.org>.
- *
- * Sat Jan 10 15:00:18 CET 1998: Martin Schulze <joey@infodrom.north.de>
- *	Fixed problem with klogd not being able to be built on a kernel
- *	newer than 2.1.18.  It was caused by modified structures
- *	inside the kernel that were included.  I have worked in a
- *	patch from Alessandro Suardi <asuardi@uninetcom.it>.
- *
- * Sun Jan 25 20:57:34 CET 1998: Martin Schulze <joey@infodrom.north.de>
- *	Another patch for Linux/alpha by Christopher C Chimelis
- *	<chris@classnet.med.miami.edu>.
- *
- * Thu Mar 19 23:39:29 CET 1998: Manuel Rodrigues <pmanuel@cindy.fe.up.pt>
- *	Changed lseek() to llseek() in order to support > 2GB address
- *	space which provided by kernels > 2.1.70.
- *
- * Mon Apr 13 18:18:45 CEST 1998: Martin Schulze <joey@infodrom.north.de>
- *	Removed <sys/module.h> as it's no longer part of recent glibc
- *	versions.  Added prototyp for llseek() which has been
- *	forgotton in <unistd.h> from glibc.  Added more log
- *	information if problems occurred while reading a system map
- *	file, by submission from Mark Simon Phillips <M.S.Phillips@nortel.co.uk>.
- *
- * Sun Jan  3 18:38:03 CET 1999: Martin Schulze <joey@infodrom.north.de>
- *	Corrected return value of AddModule if /dev/kmem can't be
- *	loaded.  This will prevent klogd from segfaulting if /dev/kmem
- *	is not available.  Patch from Topi Miettinen <tom@medialab.sonera.net>.
- *
- * Tue Sep 12 23:11:13 CEST 2000: Martin Schulze <joey@infodrom.ffis.de>
- *	Changed llseek() to lseek64() in order to skip a libc warning.
- */
-
-/* Includes. */
-#include "config.h"
-#include <stdio.h>
-#include <stdlib.h>
-#include <ctype.h>
-#include <unistd.h>
-#include <signal.h>
-#include <string.h>
-#include <errno.h>
-#include <sys/fcntl.h>
-#include <sys/stat.h>
-#if !defined(__GLIBC__)
-#include <linux/time.h>
-#include <linux/module.h>
-#else /* __GLIBC__ */
-#include "module.h"
-#endif /* __GLIBC__ */
-#include <stdarg.h>
-#include <paths.h>
-#include <linux/version.h>
-
-#include "rsyslog.h"
-#include "imklog.h"
-#include "ksyms.h"
-#include "debug.h"
-
-#define KSYMS  "/proc/kallsyms"
-
-static int num_modules = 0;
-struct Module *sym_array_modules = (struct Module *) NULL;
-
-static int have_modules = 0;
-
-
-/* Function prototypes. */
-static void FreeModules(void);
-static int AddSymbol(const char *);
-struct Module *AddModule(const char *);
-static int symsort(const void *, const void *);
-
-/* Imported from ksym.c */
-extern int num_syms;
-
-
-/**************************************************************************
- * Function:	InitMsyms
- *
- * Purpose:	This function is responsible for building a symbol
- *		table which can be used to resolve addresses for
- *		loadable modules.
- *
- * Arguements:	Void
- *
- * Return:	A boolean return value is assumed.
- *
- *		A false value indicates that something went wrong.
- *
- *		True if loading is successful.
- **************************************************************************/
-extern int InitMsyms(void)
-{
-
-        auto int        rtn,
-                        tmp;
-        FILE *ksyms;
-        char buf[128];
-        char *p;
-
-	/* Initialize the kernel module symbol table. */
-	FreeModules();
-
-       ksyms = fopen(KSYMS, "r");
-
-        if ( ksyms == NULL ) {
-                if ( errno == ENOENT )
-                        imklogLogIntMsg(LOG_INFO, "No module symbols loaded - "
-                               "kernel modules not enabled.\n");
-                else
-                        imklogLogIntMsg(LOG_ERR, "Error loading kernel symbols " \
-                               "- %s\n", strerror(errno));
-                return(0);
-        }
-
-	dbgprintf("Loading kernel module symbols - Source: %s\n", KSYMS);
-
-        while ( fgets(buf, sizeof(buf), ksyms) != NULL ) {
-                if (num_syms > 0 && index(buf, '[') == NULL)
-                        continue;
-
-                p = index(buf, ' ');
-
-                if ( p == NULL )
-                        continue;
-
-                if ( buf[strlen(buf)-1] == '\n' )
-                        buf[strlen(buf)-1] = '\0';
-                /* overlong lines will be ignored above */
-
-                AddSymbol(buf);
-        }
-
-	if(ksyms != NULL)
-		fclose(ksyms);
-
-        have_modules = 1;
-
-        /* Sort the symbol tables in each module. */
-        for (rtn = tmp = 0; tmp < num_modules; ++tmp) {
-                rtn += sym_array_modules[tmp].num_syms;
-                if ( sym_array_modules[tmp].num_syms < 2 )
-                        continue;
-                qsort(sym_array_modules[tmp].sym_array, \
-                      sym_array_modules[tmp].num_syms, \
-                      sizeof(struct sym_table), symsort);
-        }
-
-        if ( rtn == 0 )
-                imklogLogIntMsg(LOG_INFO, "No module symbols loaded.");
-        else
-                imklogLogIntMsg(LOG_INFO, "Loaded %d %s from %d module%s", rtn, \
-                       (rtn == 1) ? "symbol" : "symbols", \
-                       num_modules, (num_modules == 1) ? "." : "s.");
-
-        return(1);
-}
-
-
-static int symsort(const void *p1, const void *p2)
-{
-	auto const struct sym_table	*sym1 = p1,
-					*sym2 = p2;
-
-	if ( sym1->value < sym2->value )
-		return(-1);
-	if ( sym1->value == sym2->value )
-		return(0);
-	return(1);
-}
-
-
-extern void DeinitMsyms(void)
-{
-	FreeModules();
-}
-
-
-/**************************************************************************
- * Function:	FreeModules
- *
- * Purpose:	This function is used to free all memory which has been
- *		allocated for the modules and their symbols.
- *
- * Arguements:	None specified.
- *
- * Return:	void
- **************************************************************************/
-static void FreeModules()
-{
-        auto int        nmods,
-                        nsyms;
-        auto struct Module *mp;
-
-        /* Check to see if the module symbol tables need to be cleared. */
-        have_modules = 0;
-        if ( num_modules == 0 )
-                return;
-
-        if ( sym_array_modules == NULL )
-                return;
-
-        for (nmods = 0; nmods < num_modules; ++nmods) {
-                mp = &sym_array_modules[nmods];
-                if ( mp->num_syms == 0 )
-                        continue;
-
-                for (nsyms= 0; nsyms < mp->num_syms; ++nsyms)
-                        free(mp->sym_array[nsyms].name);
-                free(mp->sym_array);
-                if ( mp->name != NULL )
-                        free(mp->name);
-        }
-
-        free(sym_array_modules);
-        sym_array_modules = (struct Module *) NULL;
-        num_modules = 0;
-        return;
-}
-
-
-/**************************************************************************
- * Function:    AddModule
- *
- * Purpose:     This function is responsible for adding a module to
- *              the list of currently loaded modules.
- *
- * Arguments:   (const char *) module
- *
- *              module:->       The name of the module.
- *
- * Return:      struct Module *
- **************************************************************************/
-
-struct Module *AddModule(module)
-     const char *module;
-{
-        struct Module *mp;
-
-        if ( num_modules == 0 ) {
-                sym_array_modules = (struct Module *)MALLOC(sizeof(struct Module));
-
-                if ( sym_array_modules == NULL )
-                {
-                        imklogLogIntMsg(LOG_WARNING, "Cannot allocate Module array.\n");
-                        return NULL;
-                }
-                mp = sym_array_modules;
-        } else {
-                /* Allocate space for the module. */
-                mp = (struct Module *) \
-                        realloc(sym_array_modules, \
-                                (num_modules+1) * sizeof(struct Module));
-
-                if ( mp == NULL )
-                {
-                        imklogLogIntMsg(LOG_WARNING, "Cannot allocate Module array.\n");
-                        return NULL;
-                }
-
-                sym_array_modules = mp;
-                mp = &sym_array_modules[num_modules];
-        }
-
-        num_modules++;
-        mp->sym_array = NULL;
-        mp->num_syms = 0;
-
-        if ( module != NULL )
-                mp->name = strdup(module);
-        else
-                mp->name = NULL;
-
-        return mp;
-}
-
-
-/**************************************************************************
- * Function:	AddSymbol
- *
- * Purpose:	This function is responsible for adding a symbol name
- *		and its address to the symbol table.
- *
- * Arguements:	const char *
- *
- * Return:	int
- *
- *		A boolean value is assumed.  True if the addition is
- *		successful.  False if not.
- **************************************************************************/
-static int AddSymbol(line)
-        const char *line;
-{
-        char *module;
-        unsigned long address;
-        char *p;
-        static char *lastmodule = NULL;
-        struct Module *mp;
-
-        module = index(line, '[');
-
-        if ( module != NULL ) {
-                p = index(module, ']');
-                if ( p != NULL )
-                        *p = '\0';
-                p = module++;
-                while ( isspace(*(--p)) )
-			/*SKIP*/;
-                *(++p) = '\0';
-        }
-
-        p = index(line, ' ');
-
-        if ( p == NULL )
-                return(0);
-
-        *p = '\0';
-
-        address  = strtoul(line, (char **) 0, 16);
-
-        p += 3;
-
-        if ( num_modules == 0 ||
-             ( lastmodule == NULL && module != NULL ) ||
-             ( module == NULL && lastmodule != NULL) ||
-             ( module != NULL && strcmp(module, lastmodule))) {
-                mp = AddModule(module);
-
-                if ( mp == NULL )
-                        return(0);
-        } else
-                mp = &sym_array_modules[num_modules-1];
-
-        lastmodule = mp->name;
-
-        /* Allocate space for the symbol table entry. */
-        mp->sym_array = (struct sym_table *) realloc(mp->sym_array, \
-                (mp->num_syms+1) * sizeof(struct sym_table));
-
-        if ( mp->sym_array == (struct sym_table *) NULL )
-                return(0);
-
-        mp->sym_array[mp->num_syms].name = strdup(p);
-        if ( mp->sym_array[mp->num_syms].name == (char *) NULL )
-                return(0);
-
-        /* Stuff interesting information into the module. */
-        mp->sym_array[mp->num_syms].value = address;
-        ++mp->num_syms;
-
-        return(1);
-}
-
-
-
-/**************************************************************************
- * Function:	LookupModuleSymbol
- *
- * Purpose:	Find the symbol which is related to the given address from
- *		a kernel module.
- *
- * Arguements:	(long int) value, (struct symbol *) sym
- *
- *		value:->	The address to be located.
- * 
- *		sym:->		A pointer to a structure which will be
- *				loaded with the symbol's parameters.
- *
- * Return:	(char *)
- *
- *		If a match cannot be found a diagnostic string is printed.
- *		If a match is found the pointer to the symbolic name most
- *		closely matching the address is returned.
- *
- * TODO: We are using int values for the offset, but longs for the value
- * values. This may create some trouble in the future (on 64 Bit OS?).
- * Anyhow, I have not changed this, because we do not seem to have any
- * issue and my understanding of this code is limited (and I don't see
- * need to invest more time to dig much deeper).
- * rgerhards, 2009-04-17
- **************************************************************************/
-extern char * LookupModuleSymbol(value, sym)
-        unsigned long value;
-        struct symbol *sym;
-{
-        int        nmod, nsym;
-        struct sym_table *last;
-        struct Module *mp;
-        static char ret[100];
-
-        sym->size = 0;
-        sym->offset = 0;
-        if ( num_modules == 0 )
-                return((char *) 0);
-
-        for (nmod = 0; nmod < num_modules; ++nmod) {
-                mp = &sym_array_modules[nmod];
-
-                /* Run through the list of symbols in this module and
-                 * see if the address can be resolved.
-		 */
-                for(nsym = 1, last = &mp->sym_array[0];
-                    nsym < mp->num_syms;
-                    ++nsym) {
-                        if ( mp->sym_array[nsym].value > value )
-                        {
-                           if ( sym->size == 0 ||
-                                 (int) (value - last->value) < sym->offset ||
-                                 ( (sym->offset == (int) (value - last->value)) &&
-                                   (int) (mp->sym_array[nsym].value-last->value) < sym->size ) )
-                            {
-                                sym->offset = value - last->value;
-                                sym->size = mp->sym_array[nsym].value - last->value;
-                                ret[sizeof(ret)-1] = '\0';
-                                if ( mp->name == NULL )
-                                        snprintf(ret, sizeof(ret)-1,
-                                                 "%s", last->name);
-                                else
-                                        snprintf(ret, sizeof(ret)-1,
-                                                 "%s:%s", mp->name, last->name);
-                            }
-                            break;
-                        }
-                        last = &mp->sym_array[nsym];
-                }
-        }
-
-        if ( sym->size > 0 )
-                return(ret);
-
-        /* It has been a hopeless exercise. */
-        return(NULL);
-}